Chemical Engineering - Mass Transfer - Discussion
Discussion Forum : Mass Transfer - Section 1 (Q.No. 27)
27.
Dew point of a gas-vapour mixture
Discussion:
21 comments Page 1 of 3.
Kiran said:
6 years ago
Both C ad D correct.
As pressure increases dew point increases as pressure decreases dew point decreases.
Compression and expansion of air affect its dew point. Generally speaking, compression increases dew point, and expansion (i.e De-compression) lowers dew point. For example, consider compressed air leaving a dryer at 200 PSIG with a pressure dew point of -40° F/C at 200 psig. If the pressure is eventually reduced to 100 psig, the pressure dew point will fall to -50 °F at 100 psig. If the air is further expanded to 5 psig, the pressure dew point becomes -77° F at 5 psig.
As pressure increases dew point increases as pressure decreases dew point decreases.
Compression and expansion of air affect its dew point. Generally speaking, compression increases dew point, and expansion (i.e De-compression) lowers dew point. For example, consider compressed air leaving a dryer at 200 PSIG with a pressure dew point of -40° F/C at 200 psig. If the pressure is eventually reduced to 100 psig, the pressure dew point will fall to -50 °F at 100 psig. If the air is further expanded to 5 psig, the pressure dew point becomes -77° F at 5 psig.
(1)
SKS said:
4 years ago
At dew point vapour convert in liquid by using latent heat at constant temp according to latent haet definition.
Assume we have pot in this pot some vapours are present if pressure increase in this pot vapour will be condensed but in another condition, we have liquid in pot at constant volume let 2 atm pressure on it if we decrease pressure then the B P will decrease in liquid is flashed and more vapours will be formed so and vapour molecules loss it's energy and get cooled and after that condensed and d p will be increased.
Assume we have pot in this pot some vapours are present if pressure increase in this pot vapour will be condensed but in another condition, we have liquid in pot at constant volume let 2 atm pressure on it if we decrease pressure then the B P will decrease in liquid is flashed and more vapours will be formed so and vapour molecules loss it's energy and get cooled and after that condensed and d p will be increased.
Shashank said:
1 decade ago
For a given temperature D.P. is independent of Pressure. But when both temperature and pressure increases D.P. also increases and relative humidity decreases accordingly.
Vinod kumar said:
9 years ago
Liquids have high pressure than gasses. So, at high-pressure vapor condensate at high temperature. Less cooling is required for condensation at high pressure.
Rajendra Pal said:
6 years ago
Dew point is independent of temperature and directly proportional of pressure so C and D both option is correct.
Alpesh Solanki said:
9 years ago
Both c & d were correct answer because dew point is directly proportional to the pressure as simple as that.
Rajkumar Pegu said:
3 years ago
Since, the dew point is directly proportional to the pressure, so both the option C&D is correct.
(2)
Komal said:
10 years ago
When vapor pressure increase D.P also increase or not? Please someone give description.
Vicky said:
3 years ago
D. P. Proportional pressure.
So, both C&D is correct.
So, both C&D is correct.
(3)
Ajju said:
8 years ago
Yeah, Both should be right. I also agree @Alpesh.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers